450 



BIRD. 



begins ; for there are species in the middle of th 

 group, partaking in nearly an equal degree of th 

 habits of those at both extremities. The divers hav 

 the tarsi short, the tibiae rather lengthened, whiel 

 throws the joint of the tarsus backward ; the toes am 

 webs larger, and the hind toe with a little web. The) 

 do not dive habitually ; for though they are les 

 fitted for dabbling than the others, they do practis< 

 it a little, and they also feed alonw- the strands ; bu 

 they often appear to get down for change of motion 

 as well as for food ; and on such occasions they mov 

 more quickly below the water than they can on the 

 surface. 



Of course when they are once down, and the water 

 has closed over them, there is no more paddling with 

 the alternate feet. That is properly a land motion 

 and can be used as the sole means of progression 

 only when part, at least, of the body is in a rarer 

 medium than that against which the foot acts. Thus 

 when the bird is under, it immediately brings all the 

 four extremities into action, in the same manner as is 

 done by frogs, water-tortoises, and all other animal 

 which have four extremities and swim immersed. 



This is the style in which man swims, and also 

 those mammalia which have not a trotting pace be- 

 tween the slow walk and the gallop, the common pig 

 for instance. It is also the style of all aquatic mam- 

 malia, and indeed of all vertebrated animals which 

 inhabit, the waters ; for those which have no fins ol 

 any sort cannot advance with one flexure of the body, 

 hut must twine in two or more, eel-fashion, according 

 to their length. The golden-eye is the duck, visiting 

 the British shores, which has this action in greatest 

 perfection ; and the following is th^ ".^ure of its foot. 



Golden Eye. 



But even in the birds last mentioned, progressive 

 motion under water is only an occasional action, and 

 therefore they have it not in the finest style. The 

 grebes which, notwithstanding their merely lobed 

 feet, and their inhabiting ponds rank with vegetation 

 rather than the ocean or even the larger lakes, are 

 much more aquatic than the golden-eye ; and the 

 rate at which they get on under water would not be 

 believed by those who have not actually seen it. It 

 is frog-like, to be sure, from the way in which the 

 feet are worked, and the nearness to which the plane 

 of their action approaches to that of the body, but it 

 more resembles the rush of a bird through the air 

 than the swimming of any ordinary air-inhabitant in 

 the water. Among all the diving birds, from the 

 merganser to the penguin, which, although not the 

 swiftest, perhaps, in the water, is the one which de- 

 pends most exclusively upon aquatic motion, there is 

 not much difference in the feet, so far as can be 

 shown by a figure. The chief distinctions consist in 

 lite ie^b uciiig placed further backward, and the tarsi. 



being shorter and stouter, the more exclusively that 

 the bird is restricted to the motions of swimming and 

 diving. The joints have also more oblique motion, 

 mid t he-re appear to be some peculiar muscles upon 

 the tarsus, which assist in the curious twisting motions 

 of the feet, which of course increase as the wings 

 become less efficient as organs of support and balance. 

 But the most curious motions of these birds arc ail 

 performed in the sea, arid under water, so that thev 

 are rarely seen, and the subject is one upon which it 

 is by no means safe to speculate, as we have not upon 

 land any analogy to which we can trust. Tin; fol- 

 lowing is a sketch of one of the feet ; but we should 

 not be able to illustrate the mode of action, even if we 

 gave ever so accurate a figure of the bird itself. 



The feet which have been now described, or rather 

 simply noticed, carry their owners down into the 

 depths of the ocean as far as winged creatures can 

 descend; and as the knowledge of them is nearly as 

 dark and downward as the places of their resort, it is 

 rather pleasant to escape from them, and once more 

 visit the sun and the sky, the cheerer and the abode 

 of the more typical birds. 



We have, next in order, to notice those feet which 

 are entirely webbed, that is, which have the hind toe 

 included in the web as well as the three front ones. 

 At first, one would be apt to conclude that these, as 

 being the most webbed, are the most aquatic, or the 

 best swimming feet of the whole. But such is not 

 the case in fact ; and when we come to consider the 

 matter a little more closely, we find that such ought 

 not to be the case, according to the structural analogy. 

 The back toe of a bird, whether its path be upon the 

 and or the water, is never an auxiliary to the foot in 

 merely progressive motion; it is always rather the 

 reverse, and placed there in accordance with some- 

 thing else ; and thus the produced hind toe, which is 

 rudimental or wanting in all birds which have their 

 motion confined either to the surface of the earth or 



the water, indicates an aerial character in this 

 *roup. Accordingly, the pelicans, cormorants, darters, 

 and several others which have feet of this description, 

 often migrate inland, and perch and also build in trees ; 

 nd even those which never or rarely quit the sea, 

 uild high upon the cliffs, and take their repose upon 

 he land, while some of the swimmers fold their head 

 under their wing and sleep in safety upon the water. 



These birds have the feet differently articulated in 

 he different genera ; as, for instance, the cormorant 

 las them much farther back than the gannet, and is 

 iot able to carry the axis of its body in so horizontal 

 position. But they all " stand well " on their leg?, 

 nly the feet, in consequence of that form which is 

 equired to answer the habit of the bird in feeding, 

 ome rather into contact with each other, and render 

 le walk awkward and swinging. The tarsi are per- 

 endicular or nearly so ; but they are thrown wide of 

 ach other by the position of the tibiae ; and it is to 



